In the ignition system of an internal combustion engine, high voltage for causing sparking is supplied from the distributor to the spark plugs by ignition cables. There are several types of ignition cables but they typically have a conductive core encompassed by a jacket of insulation, such as rubber. Older designs of ignition cables included a metallic core. More recent designs are of the resistive type for suppressing radio frequency interference. Such designs may have a conductive core formed of fiberglass strands bonded together with a bonding material impregnated with carbon, or a very fine resistance wire might be wound around a bundle of fiberglass strands.
These ignition cables are customarily terminated for connection to the spark plug terminal after a portion of the jacket is removed and the core is folded back over the remaining jacket at the end of the cable. The electrical terminal for the ignition cable has a barrel for receiving the dressed cable end. Special tooling may be required to radially indent the barrel to compressively hold the cable and to establish good contact with the exposed core. For a more detailed explanation of the structure and operation of such prior art terminals, reference may be made to U.S. Pat. Nos. 2,816,276 and 3,518,606.
Another prior art design is for application in the field using only a pair of pliers. This terminal has a channel-shaped barrel having a pair of arms which are individually bent over the cable end to compressively hold the cable. Operator judgment is required in determining how forcefully to deform the arms.